How to Clean Data with Python: Course OverviewCourse Overview

How to Clean Data with Python

Some say data scientists spend 80% of their time cleaning data and 20% of their time doing analysis. Learn how to do this 80% in Python!

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Key Concepts

Review core concepts you need to learn to master this subject

Character Sets in Regular Expressions

Optional Quantifiers in Regular Expressions

Literals in Regular Expressions

Fixed Quantifiers in Regular Expressions

Alternation in Regular Expressions

Anchors in Regular Expressions

Regular Expressions

Wildcards in Regular expressions

Character Sets in Regular Expressions

Regular expression character sets denoted by a pair of brackets [] will match any of the characters included within the brackets. For example, the regular expression con[sc]en[sc]us will match any of the spellings consensus, concensus, consencus, and concencus.

Introduction to Regular Expressions

Lesson 1 of 2

1
Introduction
When registering an account for a new social media app or completing an order for a gift online, nearly every piece of information you enter into a web form is validated. Did you enter a properly f…
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2
Literals
The simplest text we can match with regular expressions are literals. This is where our regular expression contains the exact text that we want to match. The regex a, for example, will match …
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3
Alternation
Do you love baboons and gorillas? You can find either of them with the same regular expression using alternation! Alternation, performed in regular expressions with the pipe symbol, |, allows…
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4
Character Sets
Spelling tests may seem like a distant memory from grade school, but we ultimately take them every day while typing. It’s easy to make mistakes on commonly misspelled words like consensus, and on t…
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5
Wild for Wildcards
Sometimes we don’t care exactly WHAT characters are in a text, just that there are SOME characters. Enter the wildcard .! Wildcards will match any single character (letter, number, symbol or …
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6
Ranges
Character sets are great, but their true power isn’t realized without ranges. Ranges allow us to specify a range of characters in which we can make a match without having to type out each ind…
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7
Shorthand Character Classes
While character ranges are extremely useful, they can be cumbersome to write out every single time you want to match common ranges such as those that designate alphabetical characters or digits. To…
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8
Grouping
Remember when we were in love with baboons and gorillas a few exercises ago? We were able to match either baboons or gorillas using the regex baboons|gorillas, taking advantage of the | symbol. Bu…
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9
Quantifiers - Fixed
Here’s where things start to get really interesting. So far we have only matched text on a character by character basis. But instead of writing the regex \w\w\w\w\w\w\s\w\w\w\w\w\w, which would mat…
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10
Quantifiers - Optional
You are working on a research project that summarizes the findings of primate behavioral scientists from around the world. Of particular interest to you are the scientists’ observations of humor in…
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11
Quantifiers - 0 or More, 1 or More
In 1951, mathematician Stephen Cole Kleene developed a system to match patterns in written language with mathematical notation. This notation is now known as regular expressions! In his honor, the…
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12
Anchors
When writing regular expressions, it’s useful to make the expression as specific as possible in order to ensure that we do not match unintended text. To aid in this mission of specificity, we can u…
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13
Review
Do you feel those regular expression superpowers coursing through your body? Do you just want to scream ah+ really loud? Awesome! You are now ready to take these skills and use them out in the wild…
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